This invention relates to a universal joint of the type comprising first and second parts, wherein the first part defines a recess configured to receive a drive stud of a torque transmitting tool and the second part comprises a drive stud configured to engage a tool head. At least one coupling element is positioned between the first and second parts to transmit torque therebetween while allowing the first and second parts to rotate with the first part positioned in a skew orientation with respect to the second part.
Universal joints of this type are in common use with torque transmitting tools such as socket wrenches. See for example the constant velocity type universal joint described in Hazebrook U.S. Pat. No. 4,941,8622. Conventional universal joints include a spring biased detent ball on the drive stud that engages the recess of the tool head that is mounted to the universal joint to provide a retention force that cannot be readily altered or selected by the user.
This arrangement is not without disadvantages. In particular, on some occasions it would be preferable if a tool head were held in place in the drive stud more securely and more positively. On other occasions it would be preferable if a tool head could be released from the drive stud so as to drop freely from the drive stud and allow one hand removal of the tool head mounted on the drive stud.